Pet Sayings: Canary in a coal mine

As the Police song says,”First to fall over when the atmosphere is less than perfect,” life for an actual canary in a coal mine in the early 1900s could be summed up in three words: short but meaningful. The bright yellow birds were an early coal miner’s life insurance policy.

Because coal mines weren’t equipped with ventilation systems, miners would routinely bring a caged canary down into the shafts to help detect the build up of dangerous levels of methane and carbon monoxide (which are odorless, tasteless, and colorless to humans).

According to the Mine Safety Health Adminstration (MSHA), canaries were preferred over mice because when exposed to the noxious gases, “a canary would sway noticeably on his perch before falling.” As long as the canary kept singing, the miners could be assured that their air supply was safe. A dead canary signaled the need for an immediate evacuation. Some mining companies continued to rely on canaries well into the 20th century, even as gas-detection technology improved.

The expression, “canary in a coal mine” is now used to mean an early indicator or harbinger of the future. (As in, “The initial sub-prime defaults were the canary in the coal mine for the economy on the whole;” or “The retreating glaciers in Alaska are a canary in a coal mine for global warming.”) Saying that someone “lives like a canary in a coal mine” suggests a willingness of that person to live life on the edge, or to experience life’s dangers without compromise.